I have hostas that get eaten up every year very badly and I decided to address it. The damage appearance seems like nematode attack so I found this article that suggests an early spring drench with ammonia. It says to use a 10% amonia solution and im not sure what that is. Regular store bought ammonia says it is usually 5-10% ammonia according to 'internet sources'. But I'm assuming the author means to make a 1:10 solution of the 'already 10% store bought' ammonia with water. Can anyone comment on whether this may be correct or not? I tried to contact the author but did not get a response.

https://worldofgardenplants.co...

P.S. I have already tried anti-slug treatments and insecticides.

Pic of the damage would help, general location would also be helpful

Thanks. I don't have photos of them, but basically large portions of leaves like half the leaf or more on a lot of leaves appear to be chewed off from the edges but also long sections of leaf btwn the veins turn brown and develop lots of holes. I treated with Sluggo last year, general insecticide, neem oil, and a light peroxide solution. The peroxide damaged the leaves too much but they survived. The front of the house faces West, and the hostas are in the garden adjacent to the house which extends about 5 feet from the house. There are 4 or 5 hostas w/ green and white striped leaves and they get about 4 feet wide and 3 feet tall, pretty big. They've been growing larger every year. I think some of the damage is prob due to excessive sun since they get direct sun a good portion of the day unfortunately. But I didn't plant them they were here when I moved in. After I did all the treatments listed there was improvement (lasted longer into the season) but I still got similar damage so I am suspecting nematodes from some research. There are no shoots yet so I am eager to try the ammonia drench if I can just figure out how to do it.

Just a thought, but if more than half of the leaf is chewed off from the outside in, it sounds like it could be a critter, probably deer.

@ViolaAnn

Ann has talked about the ammonia drench, believe she uses 20-1, water to ammonia.

I'm confused. Your description suggests critter damage and possibly FOLIAR nematodes. Am I mistaken that the ammonia remedy is for ROOT KNOT nematodes? Here are a couple of articles with photos that might help you diagnose the pests attacking your hostas. Your photos sure would help if you can manage it.

https://hort.extension.wisc.ed...

Click on "Herbaceous perennials" in the index for this article
https://www.canr.msu.edu/resou...

crawgarden said: @ViolaAnn

Ann has talked about the ammonia drench, believe she uses 20-1, water to ammonia.

When you say 20-1, do you mean 1 part of "store-bought" ammonia and 20 parts water? Because store bought ammonia is supposedly about 5-10% ammonia as-bought.

I went through an episode with foliar nematodes about 15 years ago -haven't had any further issues since thank goodness- and I used bleach. I have detailed the whole process on my personal website but since I'm a new member I'm not allowed to posts links (understandable) for you to read through my experience. I'll check back to this thread in a few days and see if there's a way of adding the link to this post....

While I no longer have ALL of the varieties listed in said article I still have 'Ice Age Trail' and 'Ray of Hope' and they have never shown any signs of recurrence.

crawgarden said: Pic of the damage would help, general location would also be helpful

Here is this year's batch: The damage began already when they were about 1ft high.











I put down regular sluggo about a week ago under the leaves and near the stems. I didn't do the ammonia drench I was not confident to do it. I'd like to preserve the plants as much as possible this year. The wall you see faces West so they get sun in the afternoon and evening.

The damage shown in those pictures do not show foliar nematode damage, looks much more like slugs, snails or possible weevils. The ammonia drench is a contact killer so it's best applied with a sprayer that allows you the spray the underside of the leaves where the slugs like to hide.

Thanks. It will likely get much worse the next few months. I'll post an update.